1. Technical Field
The present invention relates to a portable electrocardiogram storing apparatus, and more particularly it relates to an electrocardiogram storing apparatus which is compact and light in weight and can store in IC (integrated circuit) memories not only electrocardiograms but also the time when the electrocardiograms are recorded.
2. Prior Art
Portable electrocardiogram storing apparatus provided with IC memories are carried by patients suffering from abnormalities of the heart, and more particularly by those patients who sometimes suffer from abnormalities of the heart in daily life but do not always show the symptoms, that is, patients suspected of a temporary arrhythmia. Upon occurrence of a subjective symptom the patient depresses a push button switch of the apparatus, which then stores the electrocardiograms during the period before and after, e.g., 40 seconds before and 20 seconds after the depression of the push button switch.
Since the apparatus is intended for use with patients whose abnormalities of the heart cannot be predicted, it has the capability of storing electrocardiogram several (e.g., five) times during a predetermined period (e.g., a week). However, if the derivation of information about the time at which the respective electrocardiograms were recorded is based upon the memory of the patient, it is difficult to assure its accuracy. Thus, it is difficult to obtain correct information on the relation between, on the one hand, each electrocardiogram, and, on the other hand, what the patient was doing, and/or what kind of symptoms the patient was suffering from when the recording was made.
Another consideration is the size and weight of the apparatus. Once the portable electrocardiogram storing apparatus is carried by the patient, it is continued to be carried until the storing of all electrocardiograms is completed or the predetermined time (e.g., a week) expires. It is therefore important to make the overall apparatus as small and as light as possible. For this to be realized, it is necessary to reduce the weight and volume of circuit components of the apparatus, and it is necessary to minimize the current consumption required for storing electrocardiograms. Further, it is necessary to minimize the current consumption which is required for storing and counting the time, so that a power source which is light in weight and small in volume suffices.